Elastic-fluid turbine.



F. UUNGSTR'OM.

ELASTIC FLUID TURBINE.

APPLICATION FILED AUG.8. 19H

1 ,269, 54:9,, Patented June 11, 1918.

Fig. Fig. 2. Fig.5. Fig.4.

' Inventor:

I FredriK-L 'un strm,

FTQ.

FREDRIK LJ'UNGSTRfiM, 0F STOCKHOLM, SWEDEN, ASSIGNOR TO TIEEOLAGET LJ'U'NGSIRGMS ANGTURBIN, A CORPORATION OF SWEDEN.

ELASTIC-FLUID TURBINE.

Specification of Letters Patent. Patgmfiged J 1 mg 111, 1%118,

Application filed August 8, 1917. Serial No. 185,018. K

To all whom it may concern:

Be it known that I, FREDRIK LJUNosTRtSM, a subject of the King of Sweden, residing at Stockholm, Swedemhave invented certain new and useful Improvements in Elastic-Fluid Turbines, of which the following is a specification.

The present invention relates to elastic fluid turbines and particularly to turbines wherein the blade carrying member is provided with a rim having projecting ridges and grooves onopposite sides and the blades are provided with U-shaped bases which fit over the rim and have complementary ridges and grooves which interlock with those on the rim. It also relates to turbines wherein the tips of theblades are provided with end or cover plates and Heads which abut each other and form a blade cover and support for the out-er ends of the blades.

The object of the invention is to provide an improved method for bringing the legs of the U-shaped blade bases into engagement with the rim so as to obtain a rigid and reliable connection between the interlocking parts, and for bringing the heads of the blades into firm engagement with each other.

For a consideration of what I believe to be novel and my invention, attention is directed to the accompanying specification and the claims appended thereto.

In the accompanying drawing, Figures 1 to 5 illustrate five successive steps or stages which may be utilized in applying 111 improved method to the fastening of the lade bases to the rim of a blade carrying member; Fig. 6 is a side elevation of a portion of a blade ring constructed after the method dlsclosed by Figs. 1 to 5; Fig. 7 is a plan view of Fig. 6'; and Figs. 8, 9 and 10 are views illustrating the application of my method to the heads on the blades of a series of adja cent blades. 1

Referring to the drawing, Figs. 1 to 7, 11 indicates a blade carrying member which may be. for example. a disk, drum, or ring, and 12 indicates blades carried thereby. The blade carrying member 11 is provided with shoulders 13 and a rim 14. upon the opposite sides of which are ridges 15 between which are grooves 16. The ridges 15 and grooves 16 slope radially inward toward the center of the blade carrying member. The blades are provided with U- shaped bases, the two legs 17 thereof being provided on their inner sides with grooves 18 and ridges 19 which are complementary to ridges 15 and grooves 16 and 'slope in the opposite direction. The blades are also preferably provided with end or cover plates 20 and heads 21 (see Figs. 8, 9 and 10) which forced together. As a result of this operation, the entire ring of blades is brought into position on the rim and properly spaced around it. The legs 17 of the blades are then pressed or squeezed toward the rim 14; to bring the complementary ridges and grooves thereon into interlocking engagement with each other. This may be done in one or more steps or operations depending on the size of the buckets and other conditions met with in any particular case. In the present instance I have illustrated two steps as follows: The legs 17 of the blades are first pressed or squeezed toward the rim 14, the pressure being chiefly applied to the inner radial ends thereof, thereby bringing the parts into the position shown in Fig. 2, after which they are subjected to a some- What greater pressure at a point more remote from the inner radial ends when the parts assume the position shown in Fig. 3,

the ridges and grooves on the rim 14 and legs 12 being fully interlocked. During this operation the blades are forced radially outward: This leaves a space between the inoutward to bring the interlocking ridges and grooves into very firm engagement. The legs 17 are now subjected to such a pressure as to produce a permanent deformation of the parts with the eliect that all clearances between the blade bases and the rim and be,

' the legs of the blade bases are sufficient to secure a tight connection under all circumstances. V

c designates a free space which remains between the outer circumference of rim 14 and the bucket base even when using a con siderable pressure.

The application of pressure to the legs 17 is preferably carried out in the following order. lhe pressure is applied to the legs of one bucket at a time, the two legs being simultaneously squeezed toward the rim. After the legs of the first blade base have been subjected to pressure, the pressure is next applied to the diametrically opposite blade on the other side of the blade carrying member 11, then to a blade located to one side, then to the opposite one, then to a blade located 45 or 135 to one side, then to the opposite one, and so on. By this method of applying the pressure a wandering of the blades along the periphery of the disk 11 is avoided, which displacement of the blades would occur in case of a successive working of adjacent blades.

Referring now to Figs. 8, 9 and 10, the blades, as already stated, are preferably provided with end plates 20 and heads 21 which are brought into contact during the assembling of the blades on the rim 14. After the blades have been assembled on the rim 14, as explained above, the joints between the heads 21 are subjected to a pressure of such a strength as to cause a permanent deformation of the portions of the heads adjacent the joints thereby bringing the heads 21 into very firm engagement with each other. Figs. 8 and 9 illustrate the appearance of the heads 21 prior to being subjected to such pressure, and Fig. 10 the appearance afterward, ein Fig. 16* indicating the indenta tions caused by the deformation.

As already stated, the adjacent surfaces the heads 21 are preferably curved as shown, but to avoid lateral displacement angular or straight contact surfaces may be used, or adjacent heads may be provided suitable interlocking or interengaging grooves projections.

claim as new and desire to secure by Letters Patent of the United States, is

The method of attaching blades having .i-shaped bases to a blade carrying member having a rim, the inner surfaces of the legs 1 of the ti -shaped bases and the sides of the naoaeeo rim being; provided with complementary ridges and grooves, and said legs .being substantially straight and spaced apart throughout their length a distance greater than the width of the rim, which comprises placing the U-shaped bases over the rim and squeezing the legs of the bases throughout their length toward the rim to bring the complementary ridges and grooves into engagement, the blades at the same time being displaced outwardly, the pressure used being such as to exceed the limit of elasticity of the material so that a permanent deformation of the material occurs.

2. The method of attaching blades having U-shaped bases to a blade carrying member having a rim and shoulders on opposite sides of the rim, the inner surfaces of the legs of the Ll-shaped bases and the sides of the rim being provided with complementary ridges and grooves, those on the rim sloping toward the center of said member, and those on the blade bases sloping away therefrom, and the slots in the U-shaped bases being wider than the thickness of the rim, which comprises placing the U-shaped bases over the rim, squeezing the legs of the bases into engagement with the rim to bring the complementary ridges and grooves into engagement, and upsetting the inner radial ends of the legs of the U-shaped bases-so as I to force the material into the space between the inner ends of the legs and said shoulders thereby forcin the blades radially outward and bringing t e complementary ridges and grooves into firm engagement.

3. The method of attaching blades having U-shaped bases to a blade carrying member having a rim and shoulders on opposite sides-of the rim, the inner surfaces of the legs of the l d-shaped bases and the sides of the rim being provided with complementary ridges and grooves, those on the rim sloping toward the center of said member, and those on the blade bases sloping away therefrom, and the slots in the U-shaped bases being wider than the thickness of the rim, which comprises placing the U-shaped bases over the rim, squeezing the legs of the bases into engagement with the rim to bring the complementary ridges and grooves into engagement, upsetting the inner radial ends of the legs of the lei-shaped bases so as to force the material into the space between the innor ends of the legs and said shoulders thereby forcing the blades radially outward and bringing the complementary ridges and grooves into iirm engagement, and then again squeezin the legs of the U-shaped bases toward the rim with a pressure sufiicien'tly great to cause a permanent deformation of the material so that the parts are brought into such tight contact that they will not be loosened by the'combined influence of centrifugal forces and heat.

4. The method of attaching blades having U-shaped bases to a blade carrying member having a rim, the slots in the U-shaped bases being wider than the thickness of the rim, 'which comprises lacing the U-shaped bases over the rim an squeezing the legs of the bases into engagement with the rim, the squeezing pressure being applied first to any one of the blades, thenjto a blade located opposite thereto, thento 'a blade located between said two opposite blades, then to a blade located opposite to the third mentioned blade, and so on.

5. The method of attaching blades having U-shaped bases to a blade carryin member having a rim, the inner surfaces 0 the legs 7 of the U-shaped bases and the sides of the T1111 being provided with complementary ridges and grooves, and the slots in the U- shaped bases being Wider than the thickness of the rim, which comprises placing the U- shaped bases over the rim and squeezing the legs of the bases into engagement with the rim so as to bring the complementary ridges and grooves into engagement, the ressure used beingsuch as to exceed the of elasticity of the material so that a permanent deformation of the material occurs,

said pressure being applied to one blade at a time and in an order other than the successive order in which the blades occur.

6. The method of attaching blades having U-shaped bases to a blade carrying member having a rim and shoulders on opposite sides ofthe rim, the inner surfaces of the legs of the U-shaped bases and the sides of the rim being provided with complementary ridges and grooves, those on the rim sloping toward the center of said member, and those on the blade bases sloping away therefrom, and the slots in the U-shaped bases being wider than the thickness of the rim, which comprises placing the U-shaped bases over the rim, squeezing the inner radial portions of the legs of the bases to cause a radially outward displacement of the blades, and then squeezing the legs onto the rim causing a permanent deformation of the same.

In Witness whereof, I have hereunto-set my hand this 22nd day of June, 1917.

FREDRIK LJUNesTRoM. 

